JP6806076B2 - Wireless devices, controls and wireless communication systems - Google Patents

Description

[Description of related applications]
The present invention is based on the Japanese patent application: Japanese Patent Application No. 2015-212520 (filed on October 29, 2015), and the entire contents of the application shall be incorporated and described in this document by citation.
The present invention relates to a wireless device, a control device, and a wireless communication system in a wireless communication system configuration in which the functions of a wireless base station are divided into a wireless device and a control device.

As a technique for improving frequency utilization efficiency in a wireless communication system, multi-user MIMO (MU-MIMO: Multi User Multiple Input Multiple Output) transmission that spatially multiplexes signals of a plurality of terminals is being studied. Non-Patent Document 1 describes a method of estimating the channel capacity for each candidate for a combination of terminals using the propagation path response of each terminal and selecting the combination of terminals having the maximum channel capacity as a terminal to be multiplexed. There is.

Further, in Patent Document 1, it is assumed that the scheduling method of MU-MIMO is scheduling only on the spatial axis (MIMO multiplex layer) and one carrier is assumed on the frequency axis, and the signal power based on the projection channel power of each user. Since it is a standard, there is a problem that interference power is not taken into consideration. Therefore, in Patent Document 1, as a MU-MIMO scheduling method consistent with a frequency scheduling method using received SINR (Signal to Interference plus Noise power Ratio), RB (Resource Block) frequency-divisioned within the system band is described. A scheduling method is described in which the reception quality (SINR) represented in two dimensions of the frequency axis and the spatial axis is simultaneously considered and assigned to the optimum user.

On the other hand, small cells with low transmission power and a narrow cell coverage range are being introduced to expand the network capacity of wireless communication systems. In Non-Patent Document 2, a C-RAN (Cloud / Centralized Radio Access Network) configuration for efficiently operating a small cell is studied. In C-RAN, the baseband processing function of the small cell is divided into a wireless device on the antenna side and a control device on the core network side, and the control device integrates a part of the baseband processing function of multiple small cells. Be done. Non-Patent Document 2 describes a plurality of types of C-RAN configurations according to the division method of the baseband processing function, and the transmission required for the transmission line (front hole) between the wireless device and the control device depending on each configuration. The capacity and the ease of coordinated control between cells are described.

Japanese Patent No. 5206945

J.Liu, X.She, L.Chen, “A low complexity capacity-greedy user selection scheme for zero-forcing beamforming,” VTC Spring 2009, Apr. 2009. Small Cell Forum, “Small cell virtualization functional splits and use cases,” ver.159.05.1.01, June 2015.

However, as described above, the prior art documents do not consider the use of MU-MIMO transmission in a C-RAN configuration. Therefore, in the case of the C-RAN configuration, the terminal for spatial multiplexing cannot be appropriately selected, and the application effect of MU-MIMO transmission cannot be sufficiently obtained. An object of the present invention is to provide a wireless device, a control device, and a wireless communication system that solve the problem that the application effect of MU-MIMO transmission cannot be sufficiently obtained in a C-RAN configuration.

The wireless device according to the first aspect of the present invention includes a propagation path response estimation unit that estimates the propagation path response between the wireless terminal and the own device. Further, the wireless device includes a propagation path information generation unit that generates propagation path information from the estimated propagation path response. Further, the wireless device includes a transmission unit that transmits the generated propagation path information to the control device.

The control device according to the second aspect of the present invention includes a receiving unit that receives the propagation path information generated by the wireless device based on the estimated propagation path response between the wireless terminal and the wireless device. Further, the control device includes a scheduling unit that generates scheduling information from the propagation path information. Further, the control device includes a transmission unit that transmits the scheduling information to the wireless device.

The wireless communication system according to the third aspect of the present invention includes a wireless device and a control device. The wireless device has a propagation path response estimation unit that estimates a propagation path response between the wireless terminal and the wireless device. Further, the wireless device has a propagation path information generation unit that generates propagation path information from the propagation path response. Further, the radio device has a transmission unit that transmits the propagation path information to the control device. The control device has a scheduling unit that generates scheduling information from the propagation path information. In addition, the control device has a transmission unit that transmits the scheduling information to the wireless device.

According to the present invention, since MU-MIMO transmission can be used in the C-RAN configuration, the network capacity of the wireless system is expanded.

It is a block diagram which shows the structure of the wireless communication system in this invention. It is a block diagram which shows the structural example of the center radio signal processing unit and the remote radio signal processing unit in the 1st Embodiment. It is a sequence diagram which shows the operation example of the control device and the wireless device in 1st Embodiment. It is a flowchart which shows the operation example of the scheduling part in 1st Embodiment. It is a flowchart which shows the operation example of the terminal selection of the scheduling part in 1st Embodiment. It is a flowchart which shows the operation example of the operation example of the layer number selection of the scheduling part in 1st Embodiment. It is a flowchart which shows the operation example of MCS selection of the scheduling part in 1st Embodiment. It is a block diagram which shows the structural example of the center radio signal processing unit and the remote radio signal processing unit in the 2nd Embodiment. It is a sequence diagram which shows the operation example of the control device and the wireless device in 2nd Embodiment. It is a block diagram which shows the structural example of the center radio signal processing unit and the remote radio signal processing unit in the 3rd Embodiment. It is a sequence diagram which shows the operation example of the control device and the wireless device in 3rd Embodiment. It is a block diagram which shows the structural example of the center radio signal processing unit and the remote radio signal processing unit in 4th Embodiment. It is a sequence diagram which shows the operation example of the control device and the wireless device in 4th Embodiment. It is a block diagram which shows the block diagram which shows the structural example of the control device and the wireless device in another embodiment. It is a block diagram which illustrates the structure of the wireless communication system which concerns on one Embodiment.

In MU-MIMO transmission, when a C-RAN configuration is adopted in which the wireless device and the control device are physically separated in order to operate a small cell with a narrow cell coverage range, the wireless device sends the estimated propagation path state to the control device. There was no means of notification, and scheduling by the controller was not suitable for obtaining the application effect of MU-MIMO transmission.

First, an outline of one embodiment will be described. It should be noted that the drawing reference reference numerals added to this outline are merely examples for facilitating understanding, and the present invention is not intended to be limited to the illustrated embodiment. FIG. 15 is a block diagram illustrating the configuration of the wireless communication system according to the embodiment. Referring to FIG. 15, the wireless communication system includes a wireless device 3 and a control device 200. The wireless device 3 includes a propagation path response estimation unit 327 that estimates the propagation path response between the wireless terminal 4 and the own device 3, a propagation path information generation unit 33 that generates propagation path information from the estimated propagation path response, and the like. It includes a transmission unit 34 that transmits the generated propagation path information to the control device 200. On the other hand, the control device 200 has a receiving unit 22 that receives the propagation path information generated by the wireless device 3 based on the estimated propagation path response between the wireless terminal 4 and the wireless device 3, and scheduling information from the propagation path information. A scheduling unit 214 for generating the above and a transmitting unit 23 for transmitting the scheduling information to the wireless device 3 are provided.
In the configuration of one embodiment of the present invention, in the wireless device 3, the propagation path response (Channel Response) to and from the wireless terminal 4 is estimated based on the reference signal (SRS: Sounding Reference Signal) from the wireless terminal 4. A scheduling unit 214 that includes a propagation path response estimation unit 327 and a transmission unit 34 that transmits the estimated propagation path information to the control device 200, and performs scheduling using the propagation path information received from the wireless device 3 in the control device 200. It has.

As described above, when MU-MIMO transmission is used in the C-RAN configuration, the radio device 3 is provided with the propagation path response estimation unit 327, and the control device 200 schedules using the propagation path response estimation received from the wireless device 3. It is configured to do. Therefore, when MU-MIMO transmission is used in the C-RAN configuration, the problem that resources cannot be allocated according to the state of the propagation path can be solved, and the network capacity of the wireless system can be expanded. The present invention is not limited to MU-MIMO transmission, and can be applied to other transmission methods. Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary for the sake of clarity of explanation. One of ordinary skill in the art can apply the principles and ideas grasped from the embodiments specifically described below to various types of wireless systems.
<Embodiment 1>
FIG. 1 is a block diagram showing a configuration of a wireless communication system according to the present embodiment. The wireless communication system includes a core network 100, a control device 200, a wireless device 300-1 (wireless device # 1), a wireless device 300-2 (wireless device # 2), a wireless terminal 400-1 (wireless terminal # 1), and wireless. It includes terminal 400-2 (wireless terminal # 2) and wireless terminal 400-3 (wireless terminal # 3). When it is not necessary to distinguish between the wireless devices 300-1 and 300-2, it is simply referred to as the wireless device 3. Similarly, the wireless terminals 400-1, 400-2, and 400-3 are referred to as wireless terminals 4 when no distinction is required. Further, although the wireless communication system shown in FIG. 1 includes two wireless devices 3, the number of wireless devices 3 is not limited to this. Similarly, the number of wireless terminals 4 is not limited. Further, although a wireless terminal is used as an example here, a wireless device having a relay capability may be used.

The control device 200 and the wireless device 3 are provided at physically separated positions and are connected via a transmission line 30. The transmission line 30 is a medium used for information transmission such as an optical fiber, a metal cable, and a wireless propagation line. The wireless device 3 and the wireless terminal 4 are connected via a wireless propagation path.

The control device 200 includes a center radio signal processing unit 210 and a transmission line interface 220 (transmission line IF). The transmission line interface 220 performs processing corresponding to the standard of the transmission line 30 in order to communicate with the wireless device 3 via the transmission line 30.

The radio device 3 includes a transmission line interface 310 (transmission line IF (Interface)), a remote radio signal processing unit 320, a radio transmission / reception unit 330, and an antenna 340.

The wireless terminal 4 includes an antenna and a wireless transmitter / receiver.

As shown in FIG. 2, the remote radio signal processing unit 320 in the present embodiment includes an FFT (Fast Fourier Transform) unit 326, a propagation path response estimation unit 327, an encoding unit 321 and a modulation unit 322, an antenna mapping unit 323, and a resource. It includes a mapping unit 324 and an IFFT (Inverse Fast Fourier Transform) unit 325.

The center radio signal processing unit 210 includes a scheduling unit 214, a PDCP (Packet Data Convergence Protocol) layer processing unit 211, an RLC (Radio Link Control) layer processing unit 212, and a MAC (Media Access Control) layer processing unit 213. There is. Although the processing unit of each layer is described in the center radio signal processing unit 210 as an example here, it may exist in the remote radio signal processing unit 320.

The wireless transmission / reception unit 330 of the wireless device 3 converts a wireless signal including a reference signal and the like received from the wireless terminal via the antenna 340 into a baseband signal and outputs the radio signal to the FFT unit 326.

The FFT unit 326 performs a fast Fourier transform (FFT) of the baseband signal input from the radio transmission / reception unit 330, and outputs the baseband signal to the propagation path response estimation unit 327. It should be noted that the cyclic prefix (CP: Cyclic Prefix) is removed between the FFT unit 326 and the wireless transmission / reception unit 330 (not shown).

The propagation path response estimation unit 327 uses the signal input from the FFT unit 326 and the reference signal known on the wireless device 3 side transmitted by the wireless terminal 4, and the propagation path between the wireless terminal 4 and the wireless device 3. The response is estimated, and the estimated value is output to the scheduling unit 214 and the antenna mapping unit 323 of the center radio signal processing unit 210 via the transmission line interface 310, the transmission line 30, and the transmission line interface 220. However, the wireless terminal 4 for which the propagation path response is estimated is not limited to the wireless terminal communicating with the wireless device 3, and the propagation path response to the wireless terminal communicating with another wireless device may be estimated. Further, the estimated value to be output may be averaged in the time direction or the frequency direction. The terminal may estimate the propagation path response using the reference signal and transmit the propagation path response to the wireless device.

The transmission line interface 310 performs processing corresponding to the standard of the transmission line 30 in order to communicate with the control device 200 via the transmission line 30.

The scheduling unit 214 uses the estimated value of the propagation path response input from the propagation path response estimation unit 327 of the remote radio signal processing unit 320 to provide the wireless terminal 4 with a radio resource or a modulation coding scheme (MCS). Is assigned, and the allocation information is output to the RLC layer processing unit 212, the MAC layer processing unit 213, the coding unit 321 and the modulation unit 322, the antenna mapping unit 323, and the resource mapping unit 324.

The PDCP layer processing unit 211 applies processing such as compression and encryption to the user data sent from the core network 100 and outputs the user data to the RLC layer processing unit 212.

The RLC layer processing unit 212 buffers the data input from the PDCP layer processing unit 211, divides and combines the buffered data according to the request from the scheduling unit 214, and outputs the buffered data to the MAC layer processing unit 213. ..

The MAC layer processing unit 213 multiplexes the data and control information sent from the RLC layer processing unit 212 according to the request from the scheduling unit 214, via the transmission line interface 220, the transmission line 30, and the transmission line interface 310. It is output to the coding unit 321 of the remote radio signal processing unit 320.

The coding unit 321 encodes the data input from the MAC layer processing unit 213 via the transmission line interface 220, the transmission line 30, and the transmission line interface 310 based on the information sent from the scheduling unit 214, and encodes the data to the modulation unit. Output to 322.

The modulation unit 322 converts the data input from the coding unit 321 into a modulation signal based on the information sent from the scheduling unit 214, and outputs the data to the antenna mapping unit 323.

The antenna mapping unit 323 calculates the weighting coefficient to be multiplied by the modulated signal by using the information input from the scheduling unit 214 and the estimated value of the propagation path response input from the propagation path response estimation unit 327. The antenna mapping unit 323 multiplies the calculated weighting coefficient by the modulated signal input from the modulation unit 322, adds the spatially multiplexed signal after multiplying by the weighting coefficient, and outputs the signal to the resource mapping unit 324.

The resource mapping unit 324 maps the signal input from the antenna mapping unit 323 to the radio resource based on the information input from the scheduling unit 214, and outputs the signal to the IFFT unit 325.

The IFFT unit 325 performs an inverse fast Fourier transform (IFFT) on the signal input from the resource mapping unit 324 and outputs the signal to the wireless transmission / reception unit 330. A cyclic prefix (CP: Cyclic Prefix) is added between the IFFT unit 325 and the wireless transmission / reception unit 330 (not shown).

The radio transmission / reception unit 330 converts the baseband signal transmitted from the IFFT unit 325 into a radio signal in the carrier frequency band, and transmits the radio signal via the antenna 340.

As shown in FIG. 3, the wireless device 3 in the present embodiment performs the following operations S101 to S110.

First, the wireless device 3 transmits a reference signal request to the wireless terminal 4 (operation S101). The wireless device 3 receives a reference signal from the wireless terminal 4 (operation S102). In the wireless device 3, the propagation path response estimation unit 327 estimates the propagation path response (transfer function, impulse response, etc.) of the propagation path between the wireless device 3 and the wireless terminal 4 (operation S103). The radio device 3 sends an estimated value of the propagation path response to the control device 200 (operation S104). However, the estimated value of the propagation path response to be transmitted does not have to be for all the estimated wireless terminals. For example, the wireless terminal that is not the communication partner of the wireless device 3 may be limited to the wireless terminal having a large gain of the propagation path response. Further, the control device 200 may instruct the wireless terminal to transmit the estimated value of the propagation path response, and the wireless terminal that transmits the estimated value of the propagation path response may be limited based on the instruction.

The scheduling unit 214 of the control device 200 uses the estimated value of the propagation path response sent from the radio device 3 to allocate radio resources such as terminal combination, spatial multiplexing, and modulation coding method (operation S105). The center radio signal processing unit 210 of the control device 200 buffers the data obtained by compressing and encrypting the user data, and buffers the user data according to the request from the scheduling unit 214 based on the scheduling result of the operation S105. The ringed data is divided and combined to generate transmission data (operation S106). The control device 200 sends the scheduling result of the operation S105 (combination of terminals, number of layers, MCS, etc.) to the wireless device 3 (operation S107). Further, the transmission data, the control information, and the like generated in the operation S106 are multiplexed according to the request from the scheduling unit 214 and sent to the wireless device 3 (operation S108).

The remote radio signal processing unit 320 of the wireless device 3 performs coding, modulation, weight generation, mapping, etc. on the transmission data sent in the operation S108 based on the scheduling information sent in the operation S107, and bases the data. A band signal is generated (operation S109). The wireless transmission / reception unit 330 of the wireless device 3 generates a wireless signal from the baseband signal generated in the operation S109 and transmits it via the antenna 340 (operation S110).

As shown in FIGS. 4 to 7, the detailed scheduling operation of the operation S105 in the present embodiment will be described.

The scheduling unit 214 in the present embodiment first selects a wireless terminal to communicate with from a plurality of wireless terminals (operations S501 to S504). As shown in FIG. 5, the selection of terminals will be described.

First, a certain RBG is selected from the selectable RBGs (Resource Block Group) (operation S501). Regarding RB (Resource Block), in LTE (Long Term Evolution), 12 adjacent subcarriers (180 kHz) are divided into one block at intervals of 15 kHz, and this is called RB, but it is not limited to this.

Subsequently, the priority is calculated for all terminal combinations (operation S502). The correlation of the propagation path with the selected wireless terminal may be calculated, and the priority may be calculated only for some wireless terminals having a low correlation. Further, the selection frequency of each wireless terminal may be calculated, and the priority may be calculated only for some wireless terminals having a low selection frequency. The method of calculating the priority will be described later.

The combination of terminals whose priorities have reached the specified value is assigned to the selected RBG (operation S503). Here, the term "reaching the regulation" may be, for example, a combination of terminals having the highest priority, or a combination having the highest overall priority under the condition that each terminal satisfies the minimum rate. Further, it may be compared with a preset threshold value or the like.

After assigning terminals to all RBGs, the process proceeds to the next step (operation S504).

The number of layers is selected for each of the wireless terminals selected in operations S501 to S504 (operations S601 to S604). Here, the number of layers means the number of modulated signals that multiply different weighting factors in the antenna mapping 323, that is, the number of modulated signals that are spatially multiplexed. For the sake of simplification of the following description, it is assumed that the number of layers and the number of code words, which are units of coding, are the same. The terminal and the number of layers may be selected at the same time.

As shown in FIG. 6, selection of the number of layers will be described.

First, a terminal assigned to a certain RBG is selected (operation S601). In the selected terminal, the priority is calculated for all the selectable layers (operation S602). The number of layers whose calculated priority has reached the specified value is assigned to the selected terminal (operation S603). Here, the term "reaching the regulation" may be, for example, the number of layers having the highest priority, or the number of layers having the highest priority under the condition that each terminal satisfies the minimum rate. It may also be compared with a preset threshold value or the like.

After allocating the number of layers to all RBGs, the process proceeds to the next step (operation S604).

Finally, as shown in FIG. 7, the MCS corresponding to each layer of each terminal in each RBG is selected (operations S701 to S704). First, a certain layer is selected from each layer of a certain terminal set in a certain RBG (operation S701).

The received SINR in the selected layer is calculated (operation S702). However, it is not necessary to limit the SINR to be calculated to one, and the SINR may be calculated for each of a plurality of RBs included in the RBG. The SINR calculation method will be described later.

MCS is selected based on the calculated SINR (operation S703). A SINR value satisfying a predetermined quality (for example, a packet error rate of 0.1) is set for each MCS, and the maximum is obtained under the condition that the calculated average SINR is larger than the SINR value satisfying the predetermined quality. MCS may be selected. When comparing the average SINR and the SINR satisfying a predetermined quality, an offset value may be added to the average SINR. The offset value may be a constant value, or may be changed sequentially, for example, depending on the success or failure of communication.

In all RBGs, when MCS is set in all layers of the set terminal, the process proceeds to the next step (operation S704).

In order to allocate resources, it is common to use a value that represents the priority. A high priority indicates that it is the best combination in the set. The priority M _k is calculated according to, for example, the Max-C / I norm or the PF (Proportional Fairness) norm.

In the case of the Max-C / I norm, the received SINR is estimated for the wireless terminal included in the set _Us (n) of the selected terminals and the wireless terminal with the terminal number k, and the estimated SINR is the Shannon capacity theory. It is converted into an instantaneous rate by the formula, and the sum of the instantaneous rates is _defined as M _k .

In the PF norm, radio resources are allocated at the ratio of the instantaneous throughput to the average throughput of the target mobile station. In the case of the PF norm, the sum of the instantaneous rates divided by the average rate is defined as _Mk , not the sum of the instantaneous rates.

The calculation norm of M _k may be changed for each stage. Further, in order to preferentially select a combination of terminals having a low correlation, the reciprocal of the correlation value of the propagation path between the terminals may be set to M _k .

Three examples are given as the above-mentioned parameters used for calculating the priority and the method for calculating the received SINR.

In the first example, the transmission weight (Transmission Weight) (weight coefficient to be multiplied by the modulated signal) and the reception weight (weight coefficient to be multiplied by the received signal) input from the radio device 3 using the propagation path response. And are used to estimate the SINR.

In the second example, the SINR is estimated using the propagation path response vector for each layer generated by performing matrix operation processing on the propagation path response input from the radio device 3.

In the third example, the SINR is estimated using the correlation of the propagation paths between terminals calculated from the propagation path response vector for each layer input from the wireless device 3. They are represented by the following equations (1), (3), and (6), respectively.

First, a method using weights, which is a first example of a method for calculating received SINR, will be described. As an example, consider the case of estimating the SINR of the first layer of the k-th radio terminal. The number of antennas with the N _R wireless terminal 4, the number of antennas with _{N T} a (≧ _{N R)} is the wireless device 3. _Let H _k be the _NR × _NT propagation path response matrix whose elements are the estimated value of the propagation path response between the wireless device 3 and the k-th radio terminal input from the wireless device 3. _{N T} dimensional transmission weight vectors _{w Tx} for the l layer of the k-th wireless _{terminal, k,} l, the _{N R-dimensional} reception weight vector and _{w Rx, k, l.} Let the transmission power be P _{k, l} and the interference power of other cells be σ _I ² (k, l). The set of terminals that wireless device has selected U _s, the noise power and sigma _n ^2. The received SINRγ _{k, l} of the lth layer of the kth wireless terminal is estimated by the following equation (1). However, ^H represents Hermitian transpose.

Next, a method of calculating the parameter transmission weight vector w _{Tx, k, l} used in the equation (1) will be described. The transmission weight vectors w _{Tx, k, l} are generated by the scheduling unit 214 using H _{k according} to a predetermined norm. For example, norms such as MRT (Maximum Ratio Transmission), ZF (Zero Forcing), and SLNR (Signal to Leakage plus Noise Ratio) are used.

Here, as an example, a generation method based on the ZF norm will be described. Assuming that K'radio terminals 4 from terminal numbers 1 to K'are selected for the RBG to be estimated by SINR, a propagation path response matrix for K'radio terminals 4 is combined (K'N). the _R) × _{N T} channel response matrix H and ^{_{H H = (H 1 H ···}} H K 'H). _{N T} × (K'N _R) transmission weight matrix _{W Tx} coupled a transmission weight vector for the wireless terminals is generated by ^{_{W Tx = H H (H ·}} H H) -1.

This _WTx contains _NR transmission weight vectors for each of the K'radio terminals. Transmit weight vector w _Tx of the l layer of the k-th radio _{terminal, k, l} is the product of the channel response matrix H _k and the transmission weight vector in transmission weight vector of the k radio terminal included in W _Tx The transmission weight vector having the lth largest magnitude may be selected.

Next, a method for calculating the parameters w _{Rx, k, l} used in the equation (1) will be described. The reception weight vectors w _{Rx, k, l} are generated according to a predetermined norm using H _k and w _{Tx, k, l} . As an example, when the MRC (Maximum Ratio Combining) norm is used, it is generated by the following equation (2).

The method of calculating the parameters and transmission powers _{Pk and l} used in the equation (1) will be described. The transmission powers P _{k and l} can be set, for example, by allocating equal power to each layer of the selected K'wireless terminals, or under the condition that the total power of all layers is constant, the transmission weight vector and the propagation path. A method of assigning a value according to the size of the product with the response matrix is used.

The first term of the denominator on the right side in the equation (1) is the interference power given to the k-radio terminal by the signal excluding the l-layer of the k-radio terminal. The magnitude of this interference power depends on the generation norm of the transmission weight vector. For example, when it is generated according to the ZF norm, the interference power becomes 0, and the first term of the denominator on the right side can be ignored in the calculation of the equation (1).

Next, as a second example of the method of calculating the received SINR, a method of using the propagation path response vector for each layer will be described. As an example, the reception SINRγ _{k, l} of the l-th layer of the k-th radio terminal is estimated by the following equation (3) using the propagation path response vectors g _{k, l} of the l-th layer of the k-th radio terminal. However, ^T represents transpose.

The parameters used in the equation (3) and the calculation method of the propagation path response vectors _{gk and l} of each layer will be described. The _NT- dimensional propagation path response vectors g _{k and l} of the l-th layer of the k radio terminal are expressed by the following equation (4).

However, ^* represents the complex conjugate. Since v _{k and l} form an orthonormal basis, g _{k and l} generated by Eq. (4) are orthogonal to each other between the layers. That is, the inner product of g _{k, l} and g _{k, l'} (l ≠ l') is 0. In order to obtain the propagation path response vector of each layer, λ and v are generated by performing singular value decomposition or eigenvalue decomposition on the propagation path response matrix.

A method of calculating the parameters λ and v used in the equation (4) by using the singular value decomposition will be described. N _R × N _T channel response matrix H _k for the estimated value as an element of the channel response between the wireless device and the k radio terminal can be expressed by the following equation (5).

However, the _{U k} left singular vectors _{u k, l (l = 1} , ..., N R) is a _{N R} × _{N R} unitary matrix with a column vector. V _k is an _NT × _NT unitary matrix having a right singular vector v _{k, l} (l = 1, ..., _NT ) as a column vector. Singular values of _{H k} sigma is the diagonal elements have a (eigenvalue _{λ k, l (l = 1} , ..., the square root of _{N R)),} non-diagonal component is _{N R} × _{N T} matrix of 0 .. It is assumed that the singular value (and eigenvalue) subscript numbers are assigned in descending order of value.

Subsequently, the case where the eigenvalue decomposition is used will be described. The eigenvalue decomposition is applied to the _NT × _NT matrix H _k ^H H _k to calculate the eigenvalues λ _{k, l} and the eigenvectors v _{k, l} . Before performing the singular value decomposition or the eigenvalue decomposition, H _k or H _k ^H H _k may be averaged in the time / frequency direction.

As a third example of the method of calculating the received SINR, a method using the gain and correlation (Channel Gain / Channel Correlation) of the propagation path will be described. As an example, the reception SINRγ _{k, l} of the l-th layer of the k-th radio terminal has the propagation path response vectors g _{k, l} of the l-th layer of the k-th radio terminal and the coefficients α _{k, l} indicating the gain of the propagation path. It is estimated by the following equation (6) using. The method of generating the propagation path response vectors _{gk and l} of each layer is the same as the method described in the equation (5), and thus is omitted.

The method of generating the parameters α _{k and l} indicating the gain of the propagation path and the parameters used in the equation (6) will be described. As an example, two types of calculation methods are shown, one is for the ZF norm and the other is for a large number of spatially multiplexed layers.

First, in the case of the ZF norm, since the transmission weight vector is generated so that the signals destined for the plurality of spatially multiplexed radio terminals do not interfere with each other, the gain of the desired signal is deteriorated by that amount. α _{k and l} are normalized gains that take into account the effects, and are calculated by the following equation (7).

The parameter used to derive equation (6), the correlation of the propagation path between the l-layer of the k-th radio terminal and the l'layer of the k'radio terminal ρ _{(k, l) (k', The} method of calculating _l') will be described. Using the propagation path response vectors g _{k, l} of the l-th layer of the k-th radio terminal and the propagation path response vectors g _{k', l'} of the l'layer of the k'th radio terminal, the following equation (8) is used. It is calculated.

The method of deriving α _{k and l} of the equation (7) will be described. When K'radio terminals 4 from terminal numbers 1 to K'are selected, the L × _NT propagation path response matrix G obtained by combining the propagation path response matrices of each wireless terminal is as shown in the following equation (9). Can be expressed in.

As shown in equation (9), G is derived from the L × L matrix D whose diagonal component is the norm of the propagation path response vector of each layer and whose off-diagonal component is 0, and the propagation path response vector of each normalized layer. It is represented by the product of the L × _NT matrix G'constituting. The _NT × L transmission weight matrix _WTx when the ZF norm is applied can be expressed as the following equation (10).

The product of G 'and G' ^H in formula (10) is non-diagonal elements diagonal is 1 is the correlation of the propagation path between the two layers is calculated from equation (8). G 'and G' inverse matrix of the product of ^H can be determined using the cofactor matrix, the elements of the inverse matrix can be expressed using the correlation of the propagation path between layers. By calculating the numerator on the right side of the equation (3) using the transmission weight vector derived from the equation (10) and comparing it with the numerator on the right side of the equation (6), α _{k and l} of the equation (7) can be obtained. It can be derived.

However, in the equation (7), the terms of the fourth order or higher of the correlation of the propagation path between the layers are ignored. The formulas for calculating α _{k and l} are not limited to the formula (7), and the terms of the fourth or higher order of the correlation of the propagation path between the layers may be considered, or the terms of the third order may be ignored.

Subsequently, when the number of layers (number of signals) to be spatially multiplexed is large _, the estimation of α _{k and l} using Eq. (7) is performed by ignoring the higher-order terms of the correlation of the propagation path between the layers. Accuracy deteriorates. In particular, when the value of the denominator of the second term on the right side of the equation (7) is small, the values of α _{k and l} can deviate significantly from the true value. Therefore, α _{k and l} may be derived by the following equation (11).

Compared with the case of using the equation (7), the estimation accuracy is lowered when the number of layers is small, but it is possible to avoid a large deterioration in the estimation accuracy when the number of layers is large.

The coefficient of each term is set to 1, but the coefficient is not limited to this. In addition, terms of the third order or higher of the correlation of the propagation path between layers may be considered.

Three examples are given as a method of calculating σ _I ² (k, l) indicating the interference power of another cell when the weight of the first example of the method of calculating the received SINR is used.

In the first example, the propagation path response between the radio device as the interference source and the k-th radio terminal, and the transmission weight vector (matrix) applied by the radio device as the interference source are used.

In the second example, a channel quality indicator (CQI: Channel Quality Indicator) reported from the wireless terminal 4 to the scheduling unit 214 via the wireless device 3 is used.

In the third example, the received power (RSRP: Reference Signal Received Power) of the reference signal for each cell reported from the wireless terminal 4 to the control device 2 via the wireless device 3 is used. They are represented by the following equations (12) to (14), respectively.

First, a method of calculating σ _I ² (k, l) indicating cell interference power using a transmission weight vector, which is a first example, will be described. The number of the wireless device with which the k-th terminal communicates is j, the number of the other wireless device that is the interference source is j', the set of wireless terminals selected by the j'radio device is _{Us, j',} and the j' The propagation path response matrix between the radio device and the kth radio device is H _{j', k} , and the transmission weight vector corresponding to the l'layer of the k'radio terminal communicating with the j'radio device is w _{Tx, Assuming that j', k', l'} and the transmission power are P _{j', k', l'} , σ _I ² (k, l) is calculated by the following equation (12).

Subsequently, as a second example, a method of calculating σ _I ² (k, l) indicating cell interference power using CQI will be described. The wireless terminal 4 measures the SINR using a known signal (reference signal) transmitted by the wireless device 3, compares it with the SINR threshold set for each CQI number, determines the CQI number, and wirelessly determines the CQI number. The number is reported to the scheduling unit 214 via the device 3. Assuming that the CQI reported by the kth radio terminal is CQI _k , the function for converting CQI to SINR is f (), and the correction coefficient of the interference power of other cells is μ, σ _I ² (k, l) is given by the following equation (13). Is calculated by. The value of the correction coefficient μ may be constant, or may be adaptively changed according to the success or failure of communication.

As a third example, a method of calculating σ _I ² (k, l) indicating cell interference power using RSRP will be described. Assuming that the number of the wireless device with which the kth wireless terminal communicates is j and the RSRP of the j wireless device in the kth wireless terminal is RSRP _j , σ _I ² (k, l) is given by the following equations (14) and (15). Is calculated by.

A method of calculating σ _I ² (k, l) indicating the interference power of another cell when another SINR calculation method is used will be described. The configuration of the equation for calculating the interference power shown in the equations (12), (13), and (14) can be appropriately changed depending on the method for calculating the SINR. For example, it can be transformed as the following formulas (16), (17), (18), (19), (23), and (24).

First, a method of calculating σ _I ² (k, l) indicating the interference power of another cell when the orthogonal propagation path response for each layer is used when estimating SINR will be described.

As a first example, a case where a transmission weight vector is used for estimating σ _I ² (k, l) indicating the interference power of another cell will be described. The number of the wireless device with which the k-th terminal communicates is j, the number of the other wireless device that is the interference source is j', the set of wireless terminals selected by the j'radio device is _{Us, j',} and the j' Transmission of the propagation path response vector between the wireless device and the lth layer of the kth wireless device, g _{j', k, l} , corresponding to the l'layer of the k'radio terminal communicating with the j'radio device. Assuming that the weight vector is w _{Tx, j', k', l'} and the transmission power is P _{j', k', l'} , σ _I ² (k, l) is calculated by the following equation (16).

As a second example, a case where CQI is used for estimating σ _I ² (k, l) indicating the interference power of another cell will be described. Assuming that the CQI reported by the kth radio terminal is CQI _k , the function for converting CQI to SINR is f (), and the correction coefficient of the interference power of other cells is μ, σ _I ² (k, l) is given by the following equation (17). Is calculated by.

The value of the correction coefficient μ may be constant, or may be adaptively changed according to the success or failure of communication.

As a third example, a case where RSRP is used for estimating σ _I ² (k, l) indicating the interference power of another cell will be described. Assuming that the number of the wireless device with which the kth wireless terminal communicates is j and the RSRP of the j wireless device in the kth wireless terminal is RSRP _j , σ _I ² (k, l) is calculated by the following equation (18). ..

A method of calculating σ _I ² (k, l) indicating the interference power of another cell when the correlation with the gain of the propagation path is used when estimating the SINR will be described.

As a first example, a case where a transmission weight vector is used for estimating σ _I ² (k, l) indicating the interference power of another cell will be described. The number of the wireless device with which the k-th terminal communicates is j, the number of the other wireless device that is the interference source is j', the set of wireless terminals selected by the j'radio device is _{Us, j',} and the j' The propagation path response vector between the radio device and the l-th layer of the k-th radio device is g _{j', k, l} , and the transmission power to the l'layer of the k'radio terminal communicating with the j'radio device. Assuming P _{j', k', l'} , σ _I ² (k, l) is calculated by the following equation (19).

The parameters β _{j', (k, l) (k', l')} included in the above equation are calculated by the following equation (20).

In the equation (20), the terms of the fourth order or higher of the correlation of the propagation path between the layers are ignored. The formulas for β _{j', (k, l) (k', l')} are not limited to formula (20), and terms of the fourth order or higher of the correlation of the propagation path between layers may be considered. The third-order term may be ignored.

Further, the correlation of the propagation path between the l-layer of the k-th radio terminal and the l'layer of the k'radio terminal in the j'radio device ρ _{j', (k, l) (k', l' )} Sets the propagation path response vectors g _{j', k, l} of the lth layer of the kth radio terminal and the propagation path response vectors g _{j', k', l'} of the l'layer of the k'th radio terminal. It is calculated by the following equation (21).

When the number of layers (number of signals) to be spatially multiplexed is large, β _{j', (k, l} ) derived by Eq. (20) is ignored by ignoring the higher-order terms of the correlation of the propagation path between the layers. _{) (K', l')} values can deviate significantly from the true values. Therefore, β _{j', (k, l) (k', l')} may be derived by the following equation (22).

The coefficient of each term is set to 1, but the coefficient is not limited to this. In addition, terms of the third order or higher of the correlation of the propagation path between layers may be considered.

As a second example, a case where CQI is used for estimating σ _I ² (k, l) indicating the interference power of another cell will be described. Assuming that the CQI reported by the kth radio terminal is CQI _k , the function for converting CQI to SINR is f (), and the correction coefficient of the interference power of other cells is μ, σ _I ² (k, l) is given by the following equation (23). Is calculated by.

The value of the correction coefficient μ may be constant, or may be adaptively changed according to the success or failure of communication.

As a third example, a case where RSRP is used for estimating σ _I ² (k, l) indicating the interference power of another cell will be described. Assuming that the number of the wireless device with which the kth wireless terminal communicates is j and the RSRP of the j wireless device in the kth wireless terminal is RSRP _j , σ _I ² (k, l) is calculated by the following equation (24). ..

A method for calculating the noise power σ _n ² , which is a parameter used for SINR calculation, will be described. The noise power σ _n ² is calculated by the following equation (25), where K _B is the Boltzmann constant, T is the absolute temperature, F is the noise figure, and W is the bandwidth. As the value of each parameter, for example, values such as T = 290K and F = 9dB are used. Since the SINR is calculated for each subcarrier, the value of W may be the subcarrier interval (15 kHz in LTE).

<Embodiment 2>
In the present embodiment, the radio device 3 generates an orthogonal propagation path response (Orthogonal Channel Response) for each layer using the estimated value of the propagation path response, and sends it to the control device 200.

As shown in FIG. 8, the remote radio signal processing unit 320 in the present embodiment includes an orthogonal propagation path response generation unit 351 as compared with the remote radio signal processing unit 320 in the first embodiment shown in FIG. The difference is that they are.

The orthogonal propagation path response generation unit 351 generates an orthogonal propagation path response for each layer by using the estimated value of the propagation path response between the radio device 3 and the wireless terminal 4 input from the propagation path response estimation unit 327. Then, it is output to the scheduling unit 214 and the antenna mapping unit 323 of the center radio signal processing unit 210. The wireless terminal for which the orthogonal propagation path response for each layer is generated is not limited to the wireless terminal with which the wireless device 3 communicates, and the propagation path response for each layer with respect to the wireless terminal with which the other wireless device communicates. May be generated.

Other configurations are the same as in other embodiments.

As shown in FIG. 9, in the radio device 3 in the present embodiment, the orthogonal propagation path response generation unit 351 uses the estimated value of the propagation path response as compared with the radio device 3 in the first embodiment shown in FIG. The orthogonal propagation path response for each layer is generated (operation S901), and the orthogonal propagation path response for each layer is transmitted to the control device 200 (operation S902).

The method of generating the orthogonal propagation path response for each layer in the operation S901 is the same as the method using the equation (4) of the first embodiment. That is, the eigenvalue decomposition of the product of the singular value and the right singular vector generated by the singular value decomposition of the propagation path response matrix whose elements are the estimated values of the propagation path response, or the Elmeet translocation of the propagation path response matrix and the propagation path response matrix. Using the eigenvalues and eigenvectors generated by, an orthogonal propagation path response for each layer is generated by Eq. (4). Before performing the singular value decomposition or the eigenvalue decomposition, the time / frequency direction averaging process may be performed on the product of the Hermitian transposition of the propagation path response matrix or the propagation path response matrix and the propagation path response matrix.

In the operation S902, not only the orthogonal propagation path response vector itself for each layer but also the vector norm and the propagation path response vector normalized by the norm may be transmitted to the control device 200 separately. Further, it is not necessary to transmit all the orthogonal propagation path responses generated in the operation S901, and the propagation path response to be transmitted may be limited based on the norm of the propagation path response vector. Further, the propagation path response transmitted based on the instruction from the control device 200 may be limited.

The operations other than the operations S901 and S902 are the same as those in the first embodiment. However, as the method for estimating SINR in the scheduling of operation S105, the second or third example shown in the first embodiment is used.

As described above, in the present embodiment, when MU-MIMO transmission is used in the C-RAN configuration, the wireless device is provided with an orthogonal propagation path response generator that generates an orthogonal propagation path response based on the reference signal, and the control device is provided. Scheduling is performed using the orthogonal propagation path response received from the wireless device. Therefore, the amount of communication in the front hall can be reduced as compared with the configuration in which the propagation path response estimation is transmitted from the wireless device to the control device.

<Embodiment 3>
In the present embodiment, the wireless device 3 calculates the gain of the propagation path of each layer of each wireless terminal and the correlation of the propagation path between the layers of different terminals, and sends them to the control device 200.

As shown in FIG. 10, the remote radio signal processing unit 320 in the present embodiment includes a propagation path gain / correlation calculation unit 352 as compared with the remote radio signal processing unit 320 in the second embodiment shown in FIG. The point is different.

The propagation path gain / correlation calculation unit 352 uses the orthogonal propagation path response for each layer between the wireless device 3 and the wireless terminal 4 input from the orthogonal propagation path response generation unit 351 to propagate the propagation path of each layer. The gain of the above and the correlation of the propagation path between the layers of different terminals are calculated, and they are output to the scheduling unit 214 of the center radio signal processing unit 210. The wireless terminal for which the gain of the propagation path of each layer and the correlation of the propagation path between different layers of the terminal are calculated is not limited to the wireless terminal with which the wireless device 3 communicates, and other wireless devices communicate with each other. The gain of the propagation path of each layer and the correlation of the propagation path between the layers of different terminals may be calculated for the wireless terminal. Further, the gain and correlation calculated by the propagation path gain / correlation calculation unit 352 are not limited to the gain of the propagation path of each layer and the correlation of the propagation path between layers of different terminals, and the propagation path response estimation unit 327 outputs the output. Using the estimated value of the propagation path response to be performed, the gain of the propagation path of each radio terminal may be the correlation of the propagation path between different terminals.

Other configurations are the same as in other embodiments.

As shown in FIG. 11, the radio device 3 in the present embodiment has a propagation path gain / correlation calculation unit 352 orthogonal to each layer as compared with the radio device 3 in the second embodiment shown in FIG. Using the response, the gain of the propagation path of each layer and the correlation of the propagation path between different terminal layers are calculated (operation S1101), and the calculated gain of the propagation path of each layer and the correlation of the propagation path between layers are calculated. It is transmitted to the control device 200 (operation S1102). In operation S1101, the gain of the propagation path of each layer is calculated as the norm of the orthogonal propagation path response vector for each layer. The correlation of the propagation paths between the layers is calculated from the equation (7) in the first embodiment using the orthogonal propagation path responses for each layer.

In the operation S1102, it is not necessary to transmit the gain of all the propagation paths calculated in the operation S1101 and the correlation of the propagation path between the terminals, and based on the value of the gain of the propagation path and the correlation of the propagation path between the terminals. What is transmitted may be limited. Further, the gain of the propagation path transmitted based on the instruction from the control device 200 and the correlation of the propagation path between the terminals may be limited.

The operations other than the operations S1101 and S1102 are the same as those in the second embodiment. However, as a method for estimating SINR in the scheduling of operation S105, the third example shown in the first embodiment is used.

As described above, in the present embodiment, when MU-MIMO transmission is used in the C-RAN configuration, the propagation path gain of each layer of each wireless terminal and the propagation between layers of different terminals are based on the reference signal in the wireless device. It is equipped with a propagation path gain / correlation generator that calculates the path correlation, and has a configuration in which the control device performs scheduling using the propagation path gain received from the wireless device and the correlation. Therefore, the amount of communication in the front hall can be reduced as compared with the configuration in which the orthogonal propagation path response is transmitted from the wireless device to the control device.

<Embodiment 4>
In the present embodiment, the radio device 3 generates a transmission weight matrix using the estimated value of the propagation path response and sends it to the control device 200.

As shown in FIG. 12, the remote radio signal processing unit 320 in the present embodiment is different from the remote radio signal processing unit 320 in the first embodiment shown in FIG. 2 in that it includes a transmission weight generation unit 361. .. The transmission weight generation unit 361 generates a transmission weight matrix using the estimated value of the propagation path response between the radio device 3 and the wireless terminal 4 input from the propagation path response estimation unit 327, and generates a transmission weight matrix, which is used as a center radio signal. Output to the scheduling unit 214 of the processing unit 210.

The orthogonal propagation path response unit 351 according to the second embodiment may be provided in the remote radio signal processing unit 320, and a transmission weight matrix may be generated using the orthogonal propagation path response for each layer.

Other configurations are the same as in other embodiments.

As shown in FIG. 13, in the radio device 3 in the present embodiment, the transmission weight generation unit 361 transmits using the estimated value of the propagation path response as compared with the radio device 3 in the first embodiment shown in FIG. A weight is generated (operation S1301), and the generated transmission weight is transmitted to the control device 200 (operation S1302).

In operation S1301, the transmission weight matrix is generated for each combination of several wireless terminals selected based on the correlation of propagation paths between terminals, the communication frequency of each wireless terminal, and the like. MRT, ZF, SLNR and the like are used as the transmission weight generation norms.

The operations other than the operations S1301 and S1302 are the same as those in the first embodiment.

As described above, in the present embodiment, when MU-MIMO transmission is used in the C-RAN configuration, the wireless device is provided with a transmission weight generator, and the propagation path response estimation and transmission weight received by the control device from the wireless device are used. It is configured to perform scheduling. Therefore, it is not necessary to provide the control device with a transmission weight generation function, and the cost of the control device can be reduced.

<Other Embodiments>
As described in FIG. 14, the functions included in the wireless device and the control device in each of the above-described embodiments are computer devices among the microprocessors, circuits, transmitters, receivers, and the like included in the device 1000. It may be realized by causing the (processor) 1001 to execute one or more programs. This program can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-temporary computer media include various types of real-world recording media. Examples of non-temporary computer-readable media include magnetic recording media, opto-magnetic recording media, CDs (Compact Discs), DVDs (Digital Versatile Discs), BDs (Blu-ray Discs), and semiconductor memories. The program may also be supplied to the computer by various types of temporary computer-readable media. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

The present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

In the present invention, the following forms are possible.
[Form 1]
This is the same as the wireless device according to the first aspect.
[Form 2]
The wireless device according to the first embodiment, wherein the wireless device includes a receiving unit that receives a reference signal from the wireless terminal, and the propagation path response estimation unit estimates a propagation path response based on the reference signal.
[Form 3]
The wireless device according to embodiment 1 or 2, wherein the propagation path information has a smaller amount of information than the propagation path response.
[Form 4]
The radio device according to any one of embodiments 1 to 3, wherein the propagation path information is at least one of a propagation path response, an orthogonal propagation path response, a propagation path gain, a propagation path correlation, and a transmission weight.
[Form 5]
The wireless device according to any one of embodiments 1 to 4, which is physically separated from the control device and connected to the control device via a transmission line.
[Form 6]
The wireless device according to any one of embodiments 1 to 5, wherein the wireless terminal is a wireless terminal that communicates with the wireless device or other wireless device.
[Form 7]
The wireless device includes a receiving unit that receives scheduling information from the control device, and the scheduling information includes information for spatially multiplexing resources allocated to a plurality of terminals, according to any one of embodiments 1 to 6. Wireless device.
[Form 8]
This is the control device according to the second aspect.
[Form 9]
The control device according to the eighth embodiment, wherein the propagation path response is a propagation path response estimated based on a reference signal transmitted from the wireless terminal.
[Form 10]
The control device according to embodiment 8 or 9, wherein the propagation path information has a smaller amount of information than the propagation path response.
[Form 11]
The control according to any one of embodiments 8 to 10, wherein the propagation path information is at least one of a propagation path response, an orthogonal propagation path response, a propagation path gain, a propagation path correlation, and a transmission weight. apparatus.
[Form 12]
The control device according to any one of embodiments 8 to 11, which is physically separated from the wireless device and connected to the wireless device via a transmission line.
[Form 13]
The control device according to any one of embodiments 8 to 12, wherein the wireless terminal is a wireless terminal that communicates with the wireless device or other wireless device.
[Form 14]
The control device according to any one of embodiments 8 to 13, wherein the scheduling information includes information for spatially multiplexing resources allocated to a plurality of terminals.
[Form 15]
This is the same as the wireless communication system according to the third aspect.
[Form 16]
The wireless communication system according to embodiment 15, wherein the propagation path response is a propagation path response estimated based on a reference signal received from the wireless terminal.
[Form 17]
The wireless communication system according to embodiment 15 or 16, wherein the propagation path information has a smaller amount of information than the propagation path response.
[Form 18]
The wireless communication system according to any one of embodiments 15 to 17, wherein the wireless device and the control device are physically separated and connected via a transmission line.
[Form 19]
The wireless communication system according to any one of embodiments 15 to 18, wherein the wireless terminal is a wireless terminal that communicates with the wireless device or other wireless device.
[Form 20]
The wireless communication system according to any one of embodiments 15 to 19, wherein the scheduling information includes information for spatially multiplexing resources allocated to a plurality of terminals.

30: Transmission line <network>
100: Core network <Control device>
200: Control device 22: Reception unit 23: Transmission unit 210: Center radio signal processing unit 211: PDCP layer processing unit 212: RLC layer processing unit 213: MAC layer processing unit 214: Scheduling unit 220: Transmission line IF
<Wireless device>
3, 300-1, 300-2: Radio device 33: Propagation path information generation unit 34: Transmission unit 310: Transmission line IF
320: Remote radio signal processing unit 321: Encoding unit 322: Modulation unit 323: Antenna mapping unit 324: Resource mapping unit 325: IFFT unit 326: FFT unit 327: Propagation path response estimation unit 330: Radio transmission / reception unit 340: Antenna 351 : Orthogonal propagation path response generation unit 352: Propagation path gain / correlation calculation unit 361: Transmission weight generation unit <wireless terminal>
4, 400-1 to 400-3: Wireless terminal <device>
1000: Device 1001: Processor

Claims (20)

A propagation path response estimation unit that estimates the propagation path response between the wireless terminal and the wireless device,
A propagation path information generator that generates propagation path information from the estimated propagation path response,
It includes a transmission unit that transmits the generated propagation path information to a control device that performs scheduling using the propagation path information received from the wireless device .
A wireless device characterized by that. The wireless device includes a receiving unit that receives a reference signal from the wireless terminal.
The propagation path response estimation unit estimates the propagation path response based on the reference signal.
The wireless device according to claim 1. The amount of information of the propagation path information is smaller than that of the propagation path response.
The wireless device according to claim 1 or 2. The propagation path information is at least one of a propagation path response, an orthogonal propagation path response, a propagation path gain, a propagation path correlation, and a transmission weight.
The wireless device according to any one of claims 1 to 3. Physically separated from the control device and connected to the control device via a transmission line.
The wireless device according to any one of claims 1 to 4. The wireless terminal is a wireless terminal that communicates with the wireless device or other wireless device.
The wireless device according to any one of claims 1 to 5. The wireless device includes a receiving unit that receives scheduling information generated by the control device.
The scheduling information includes information for spatially multiplexing resources allocated to a plurality of terminals.
The wireless device according to any one of claims 1 to 6. A receiver that receives the propagation path information generated by the wireless device based on the estimated propagation path response between the wireless terminal and the wireless device.
A scheduling unit that generates scheduling information from the propagation path information,
A transmission unit that transmits the scheduling information to the wireless device.
A control device characterized by that. The propagation path response is an estimated propagation path response based on a reference signal transmitted from the radio terminal.
The control device according to claim 8. The amount of information of the propagation path information is smaller than that of the propagation path response.
The control device according to claim 8 or 9. The propagation path information is at least one of a propagation path response, an orthogonal propagation path response, a propagation path gain, a propagation path correlation, and a transmission weight.
The control device according to any one of claims 8 to 10. Physically separated from the wireless device and connected to the wireless device via a transmission line.
The control device according to any one of claims 8 to 11. The wireless terminal is a wireless terminal that communicates with the wireless device or other wireless device.
The control device according to any one of claims 8 to 12. The scheduling information includes information for spatially multiplexing resources allocated to a plurality of terminals.
The control device according to any one of claims 8 to 13. Equipped with wireless device and control device
The wireless device includes a propagation path response estimation unit that estimates a propagation path response between the wireless terminal and the wireless device, and a propagation path response estimation unit.
A propagation path information generation unit that generates propagation path information from the propagation path response,
It has a transmission unit that transmits the propagation path information to the control device, and has.
The control device includes a scheduling unit that generates scheduling information from the propagation path information, and a scheduling unit.
It has a transmission unit that transmits the scheduling information to the wireless device.
A wireless communication system characterized by this. The propagation path response is an estimated propagation path response based on a reference signal received from the wireless terminal.
The wireless communication system according to claim 15. The amount of information of the propagation path information is smaller than that of the propagation path response.
The wireless communication system according to claim 15 or 16. The wireless device and the control device are physically separated and connected via a transmission line.
The wireless communication system according to any one of claims 15 to 17. The wireless terminal is a wireless terminal that communicates with the wireless device or other wireless device.
The wireless communication system according to any one of claims 15 to 18. The scheduling information includes information for spatially multiplexing resources allocated to a plurality of terminals.
The wireless communication system according to any one of claims 15 to 19.

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